Revisiting TRPC1 and TRPC6 mechanosensitivity.
Philip Gottlieb1, Joost Folgering, Rosario Maroto
1Single Molecule Biophysics, SUNY, 301 Cary Hall, Buffalo, NY 14214, USA.
Pflugers Archiv : European Journal of Physiology
|October 25, 2007
Summary
This study investigated if TRPC1 or TRPC6 channels form mammalian stretch-activated channels (MscCa). Overexpression of TRPC1 and TRPC6 did not alter MscCa activity, suggesting functional expression in cells is problematic.
Area of Science:
- Cell biology
- Ion channel physiology
- Molecular biology
Background:
- Mechanosensitive ion channels are crucial for cellular responses to mechanical stimuli.
- Transient Receptor Potential Canonical (TRPC) channels, including TRPC1 and TRPC6, have been implicated in mechanotransduction.
- The precise molecular identity of mammalian stretch-activated channels (MscCa) remains under investigation.
Purpose of the Study:
- To determine if TRPC1 or TRPC6 subunits are essential components of mammalian MscCa.
- To investigate the functional expression of TRPC1 and TRPC6 in heterologous systems regarding MscCa activity.
Main Methods:
- Transient expression of TRPC1 and TRPC6 in African green monkey kidney (COS) and Chinese hamster ovary (CHO) cells.
- Monitoring of stretch-activated channel activity using a fast pressure clamp system.
- Assessment of MscCa current amplitude following subunit overexpression.
Main Results:
- Both TRPC1 and TRPC6 were highly expressed at the protein level in the tested cell lines.
- Overexpression of TRPC1 or TRPC6 did not significantly alter the amplitude of the mechanosensitive current.
- Functional incorporation of these TRPC subunits into MscCa appears limited.
Conclusions:
- TRPC1 and TRPC6 are unlikely to be essential components of mammalian MscCa channels based on this functional analysis.
- The proposed role of TRPC1 and TRPC6 in forming MscCa in vertebrate cells requires further investigation.
- Functional expression of TRPC subunits in heterologous systems for MscCa studies presents challenges.
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